“Scientists at the Space Applications Centre (SAC), using data gathered from Chandrayaan-I's Terrain Mapping Camera and Hyper Spectral Imager (HySI) payloads, found a 1.2 km long buried, uncollapsed and near horizontal lava tube.

The scientists said the lava tubes offer a dust-free environment and adapting them for human use requires minimal construction.

The structure[s] also shields its occupants as after 6 meters depth, no effects of radiation due to or induced by galactic cosmic rays were observed in simulation, they said.
"After less than one meter, no effects of radiation due to or induced by solar particle events are observable. Natural or induced radioactivity does not play a significant role in the lava tube exposures," the scientists said.”